ML17279A294

LER 87-006-00:on 870426,after Shutdown Margin Demonstration, Reactor Protection Sys Tripped When Last Shorting Link Improperly Installed.Cause Determined to Be design-related. Terminal Strip Arrangement Will Be evaluated.W/870522 Ltr

ML17279A294
Person / Time
Site:	Columbia
Issue date:	05/22/1987
From:	Arbuckle J, Powers C WASHINGTON PUBLIC POWER SUPPLY SYSTEM
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
References
LER-87-006, LER-87-6, NUDOCS 8706050352
Download: ML17279A294 (7)

Text

REQULAT RY NFORMATION DISTR IBUTI0 SYSTEM (R IDS)

ACCESSION NBR 87060503 DOC. DATE: 8//05/22 NOTARIZED: NO DOCKET i

'I, FAC IL: 50-397 WPPSS Nuc 1eaT Pro gee t> U>>i t 2> Wash ing ton Pub 1 c Po >e 05000397 Jl i

AUTH. NAME AUTHOR AFFILIATION ARBUCKLE> J. D Washington Public Po<<er Supply System POWERS> C. M. Washington Public Pover Supply System REC IP. NAME RECIPIENT AFFILIATION

SUBJECT:

LER 87-006-00: on 870426> a~ter shutdown margin demonstral,ion>

reactor protection sos tripped when last shorting link improperly installed. Cause de+ermined to be design-related.

Terminal strip arrangement will be evaluated. W/870522 l+

DISTRIBUTION CODE: IE22D COPIES RECEIVEl): LTR ENCL SIZE:

TITLE: 50. 73 Licensee Event Report (L1=6) Incident Rpt> etc.

NOTES:

RECIPIENT COPIES RECIP I ENT COPIES ID CODE/NAl'lE LTTR ENCL ID CODE/NAME LTTR ENCL PD5 LA 1 1 PD5 PD 1 S*MWORTH R 1 INTERNAL: ACRS MICHELSON 1 1 ACRS MOELLER 2 AEOD/DOA f 1 ALOD/DSP/ROAB 2 2 AEOD/DSP/TPAB f 1 DEnRO 1 NRR/DEST/ADE 1 0 NHR/DEST/ADS 1 0 NRR/DEST/CEB 1 h!RR/DEST/ELB 1 1 NRR/DEST/ I CSB 1 1 NHR/DEST/MEB 1 1 NRR/DEST/MTB 1 NRR/DEBT/PSB 1 1 NRR/DEST/RSB 1 NRR/DEST/SGB 1 1 NRR/DLPG/HFB NRR/DLPG/GAB 1 1 NRR/DOE*/EAB 1 h!RR/DREP/RAG 1 NRR/DREP/RPB 2 2 A ILRB 1 1 NRR/PMAS/PTSB 1 1 REG F LE 0 1 1 RES DEPY QI 1 FILE Of 1 EXTERNAL: EQRG GROH> M 5 5 H ST LOBBY WARD 1 1 LPDR 1 1 NRC PDR 1 1 NSIC HARRIS J 1 1 NSIC MAYS> G 1 TOTAL NUMBER OF COPIES REQUIRED: LT1R 42 ENCL 40

US. NUCLEAR AEOULATOAYCOENIISSION NAC form 2$ $

(042) APPROVEO OMS NO. 21$ 0MIOe EXtlAKS: SISIISS LtCENSEE EVENT REPORT (LER)

DOCXET NUMSEA (2) fACILITYNAME (I) 0 5 0 0 0 1 OF Reactor Protection System Trip During Refueling Operations Due To Improper LKR NLNNKR (Sl RKtORT DATK ITI OTHER FACILITIES INVOLVKO (S)

EVENT DATE LS)

SEQUENTIAL FACI LITY NAMES DOCXET NUMSER($ )

DAY YEAR MONTH OAY YEAR YEAR NUMEEA NUMEEII MONTH O' 0 0 0 0 5 0 0 0 THIS AEfORT IS SUSMITTKD PURSUANT TO THE REOUIAKMKNTS OF 10 Cfh (I: ICneeo One Or mOre OI tne IerrerVnFI III)

DPE RAT(NO MODE (SI 20 A($(e) $ 0.124) l2) (Ie) TATI($)

20A02(EI M(eHI) $ 0.224)(2) (r) TS.TI (e)

~ OIEEA 2(L4M4)(1 I I II SO LEUK(. SOW(e) (2) $ 0 T$ 4)(2)(rS) OTHER Isoeelrf In Aortreet (10) 20.40$ le I (1)(E I Oeroreenrtln Test HhC Form

$ 0.224) l2)(l) $ 0.724)(2) (rIE) (Al JSSAI 20AOS( ~ I(1)(EI) 20AOS (e) (1)(lel SO.T $ (el(2)(E) $ 0.724II2)(rIEIIS) 20AO$ 4)(I) Iel $ 0.224) (2)(SI) SO.TS(e)(2)(e)

LICENSEE CONTACT FOA THIS LKA l12)

TELEtHONE NUMSER NAME AREA CODE J.D. Arbuckle, Compliance Engineer 50 93 77- 211 5 COMPLETE ONK LINK fOA EACH COMfONENT FAILURE DESCAISED IN THIS REPORT (12)

SYSTEM COMtONENT MANUfAC. EPORTASLE:V" :N~N@ ... 'AUSE SY$ TEM COMPONENT MANUFAC.

TURER EPORTASL TO NPRDS TUAKR TO NPRDS 3@. ')i.r,

&~4 MONTH 5~4'.OAY YEAR SUtf(.KMENTALREPORT EXPECTED i(el EXPECTED SUSMI$ SION DATE (1$ )

YES IIIPer, eomfrete fXtfCTf0 SIISMISSIDH DATE) NO ASST AACT ILImlt to IeOO eoeeee, I e., eorrrozlmetely Iilteen vnpreeneee typewrrtten llneel IIE)

On April 26, 1987 at 1933 hours0.0224 days <br />0.537 hours <br />0.0032 weeks <br />7.355065e-4 months <br />, following a shutdown margin demonstration surveillance, a Reactor Protection System (RPS) trip occurred while the last shorting link was being installed. The link for RPS subchannel B2 was inadvertently placed at the wrong terminal hoard points. This caused an electrical short in the manual scram circuit which tied two power supplies together. As a result, two manual scram circuit fuses blew, which caused a reactor scram. Since the reactor was shutdown prior to the event, no actual control rod movement occurred as a result of the scram.

The two manual scram circuit fuses were replaced, the shorting link was installed properly and the system was restored to normal shutdown status.

The root cause of this event has heen determined to be design-related in that the physical arrangement of the terminal strip in the Control Room cabinet makes it difficult to irista11 the shorting links to the rear side of the terminal strip. An Engineering evaluation will be performed to consider changing this arrangement.

870b050352 870522 0500032)7 PDR ADOGK S PDR NRC form $ $ $

(042)

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NRC Form 3SSA U.S. NUCLEAR REGULATORY COMMISSION (943 I LlCENSEE EVENT REPORT (LER) TEXT CONTlNUATION APPROVEO OMS NO. 3150&/OS EXP IR ES: 8/31/85 FACILITY NAME III OOCKET NUMSER Ill LER NUMSER ISI PACE I31 SSOVSNI'IAL Irs v IS IO N VSAA NVM SII NVMSSR Washington Nuclear Plant TEXT /I/ moro sPoro /I roqoSor/. vso ~ - Unit HiIC Form 3/EIAS/ IITI 2 o s 0 0 0 3 9 7 8 7 0 0 6 0 0 2 OF 0 3 Plant Conditions a) Power Level - O'A b) Plant Mode - 5 (Refuelinq)

Event Description On April 26, 1987 at 1933 hours0.0224 days <br />0.537 hours <br />0.0032 weeks <br />7.355065e-4 months <br />, following a shutdown margin demonstration surveillance, a Reactor Protection System (RPS) trip occurred while the last shorting link was being installed (shorting links had already been properly installed in Divisions Al, Bl, and A2). The link for RPS subchannel 82 was inadvertently placed at the wrong terminal board points (AA-70 and AA-71 instead of AA-6q and AA-70). This caused an electrical short in the manual scram circuit which tied two power supplies together. As a result, manual scram circuit fuses C72-F15C and C72-F15D blew. Loss of power to both RPS Division Manual Trip Relays resulted in a reactor scram. Since the reactor was shutdown prior to the event, no actual control rod movement occurred as a result of the scram.

The root cause of this event has been determined to be design-related in that the physical arrangement of the terminal strip in the Control Room cabinet makes it difficult to install the shortinq links to the rear side of the terminal strip.

This is particularly true of Control Room panel P611D where an existing wire is already landed at the rear side terminal, bottom screw.

Immediate Corrective Action The two manual scram circuit fuses were replaced, the shorting link was installed properly and the system was restored to normal shutdown status.

Further Corrective Action

~ The affected RPS circuitry will be checked, during routine surveillance testing, for possible damage prior to the next plant startup.

~ An Engineering evaluation will be performed to consider changing the physical arrangement of the terminal strips to allow easier installation of the shorting links.

Safety Significance There is no safety significance associated with this event in that the reactor was in cold shutdown prior to the event, there was no actual initiating condition and the RPS functioned as designed to cause a reactor scram. This event caused no threat to the safety of the public or plant personnel.

NIIC FORM SSSA

/9')

NRC Form 354A US. NUCLEAR REOULATORY COMMISSION (843)

LICENSEE EVENT REPORT ILERI TEXT CONTINUATION APPROVEO OMS NO. 3150M)(N EXPIRES: 8/31/85 FACILITY NAME (11 DOCKET NUMSER 12) LER NUMSER (5) PACE (3)

IltV I5 IO N "EAII M ttOURNTIAL NUM t II NVMttII Washington Nuclear P1ant - Vnit 2 0 5 0 0 0 0 6 0 oF0 3 TEXT IJf mcw epecre 4 IpyeirNf, IIMarftfrmefl HEMIC %%dnII 355A3) (17)

Simi1ar Events LER 86-006 E IIS Information Text Reference EIIS Refer ence System Component Reactor Protection System JC NIIC FORM 3dtA (84)3)

WASHINGTON PUBLIC POKER SUPPLY SYSTEM P.O. Box 968 ~ 3000 George Washington Way ~ Richland, Washington 99352 Docket No. 50-397 May 22, 1987 Document Control Desk U.S. Nuclear Regulatory Commission Washington, D.C. ?0555

Subject:

NUCLEAR PLANT NO. 2 LICENSEE EVENT REPORT NO.87-006

Dear Sir:

Transmitted herewith is Licensee Event Report No.87-006 for WNP-2 Plant.

This report is submitted in response to the report requirements of 10CFR50.73 and discusses the item of reportability, corrective action taken, and action taken to preclude recurr ence.

Very truly yours, 6's"t4=

C.M. Powers (M/0 927M)

WNP-2 Plant Manager CMP: 1 c

Enclosure:

Licensee Event Report No.87-006 cc: Mr. John B. Martin, NRC - Region V Mr. R. T. Dodds, NRC - Site (901A)

Mr. M. E. Milbrot, BPA (M/D 399)

INPO Records Center - Atlanta, GA Ms. Dottie Sherman, ANI Mr. C. E. Revell, BPA (M/D 399) re

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